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Looking at the circuits I got here, they all used 1k Ohm. You should have more voltage than that on the mosfet. So there is still something wrong somewhere. -
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Hello. I have done some measurings. So on the small board the IC UC3843 pin6 (output to gate) is only 0,7mV and it seems like it didn't want to drive the mosfet
How much Volts should i get on mosfet Drain and Source ?
here is a link to ic UC3843BN datasheet(1/15 Pages) STMICROELECTRONICS | HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER (alldatasheet.com)Leave a comment:
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These are the 2 connectors. So I assume the small board next to it what we were fixing it’s part of the supply.Leave a comment:
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So this is the front lcd panel with potentiometers and welding style adjustments with a small pcb it’s connected with 2 cables to the main boardLeave a comment:
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Show me what heatsink and what diode. The welder may not turn on if the low voltage supply isn’t working.Leave a comment:
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The biggest problem with an inverter welder is not continuity like voltage, it's more current based like. The circuit has to be able to carry the current. I do remember a case not too long ago, where one of the problems was burnt track on the PCB that made continuity but couldn't carry any load.
So what was your “incident”? I don't see anything blown up (yet)?Leave a comment:
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What a pain that is! Looks like it has some bad solder joints too.Leave a comment:
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Hello everyone
I attach a schematic and teardown photos for the DoCreate DHJ567 handheld spot welder. I bought this welder for temporary use while my supercapacitor welder was waiting for replacement parts. It cost only £24, though there is a screenless version available for £17.
Performance: The absolute maximum it can handle appears to be 0.15mm of pure nickel. Reliability was not great - welds were very inconsistent, ranging from weak attachment to burning through the strip. However, I was able to build a 5S2P pack without losing any cells. It's a bit difficult getting... -
Hello people. I trying to repair my Sencor TV. No standby light, not tuning on what i found there is 6V where 12V should be and 8V where 16V should be. Any suggestion?05-18-2024, 01:40 PM -
This is my own welder, that blew up while welding. There is no warranty on it. Purchased it a year ago, sealed box from Craigslist.
It worked great until now, about a year.
What I have found is a blown trace next to the main capacitors, it seems like also got damaged the SMPS IC, output MOSFET and a 1 Ohm resistor to the ground from the MOSFET.
After replacing these components, the relay, fans turn on and it sounds like it's working, but there is no output voltage for the welder, LEDs do not turn on.
So there are more components that are damaged.
I'm having a hard... -
I had my Quadra 840AV (which I recapped and had working) plugged in for some time without using it and randomly decided to turn it on today. Unfortunately it did not turn on. After checking the PSU, I found out I was not getting anything from 12V, only from the 5V rail. After a few minutes, I removed the PSU and plugged it back in the electrical outlet and it suddenly started making a weird sound and soon after smoke started coming out. I quickly unplugged it. I opened it up but on first instance I didn't see anything out of the ordinary really. I later turned it back on and one of the MOVs blew...12-22-2024, 05:07 AM -
I have a battery operated tab welder and the battery does not have enough current for the battery tab welder because after about 30 welded it does not have the same current output it voltage has gone down by at least 0.500 volts or maybe a more than that
I can fit 21700 battery cells in the enclosure it is very tight fit for four of them that are 35 amp high current capacity 35X4=140 high current output this should work a lot better than what is installed right now
I tested the battery cells there are installed right now and they are testing good with no issues that I...
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